How to create a animated silhouette?
You can use a human mesh with a shrinkwrap modifier on a plane. Let me show you an exemple:

First if you want to use an human body you can create it with makehuman and import it in blender with all the skeleton. Then you can create the animation of your human.


After that you can add the surface where you want your silhouette to be. For the exemple I used a plane.



Now you can add the shrinkwrap modifier on your human.



Now it's time to render. I've done the render with cycle, in blender internal you have problem with the superposition of the mesh like this:

So here is the final render with cycle:



Here is the video example on youtube.

And of course it works with animation. Hope this can help you.